Bug fixes

    - fstab grep did not ignore commented lines
    - zswap-related pipeline caused `bash -e` to exit on negative grep
      result on at least some versions of bash
Merge pull request #4 from edelkind/master

tmp="`grep '^[^#]*swap' /etc/fstab || :`"
     if [ ! -z "$parse_fstab" ] && [ ! -z "$tmp" ]; then
         tmp="`echo $tmp | grep '#' || :`" <<
Grep ignore lines, but my version is ugly.
I applied this patch and fix logic.